Hybrid plum tree cv. Suplumtwenty

ABSTRACT

A plum tree characterized by its large fruit, red-black color and slightly oblate shape.

This invention relates to the discovery and asexual propagation of a newvariety of hybrid plum tree, Prunus salicina cv. Suplumtwenty. The treeis an early seasoned, red-black plum cultivated for fresh fruit market.It was discovered by John H. Weinberger in an orchard of SuperiorFarming Co. (now Sun World, Inc.), in Madera County, Calif., and has asits seed parent Suplumeleven (U.S. Plant Pat. No. 4,902) and, as itspollen parent, Queen Rose (unpatented).

The new plum tree variety cv. Suplumtwenty may be distinguished fromother presently available commercial plum cultivars by the followingcombination of characteristics: its larger size, its red-black color,and slightly oblate shape. The new variety holds these distinguishingcharacteristics through succeeding asexual propagations, as for example,by grafting.

Among the characteristics which distinguish the new variety of plum treefrom its pollen parent Queen Rosa, are the following: the fruit of theSuplumtwenty variety ripens about a week later than the pollen parent.The fruit of Suplumtwenty has a much darker skin color and is muchfirmer than Queen Rosa.

The new variety may be distinguished from its seed parent, Suplumelevenin the following combination of characteristics: the fruit ofSuplumtwenty matures about two weeks earlier than Suplumeleven and islarger in size than the seed parent. The flesh of Suplumtwenty is firmerand more yellow in appearance than that of Suplumeleven. Moreover, thelenticels of the Suplumtwenty fruit are less conspicuous. There arefewer concentric cracks on the shoulders than Suplumeleven.

The accompanying drawing illustrates, in full color, a typical stem andmature leaves of the plum tree and the ripe fruit as viewed from thestem end and in profile. The drawing also illustrates the fruitsectioned in half from end to end, one-half of the fruit shown with thestone in place in the flesh and the other half shown with the stoneremoved from the flesh.

Throughout this specification, color names beginning with a small lettersignify that the name of that color, as used in common speech, is aptlydescriptive. Color names with capital letters designate values basedupon The R.H.S. Colour Chart, published by The Royal HorticulturalSociety, London.

The descriptive matter which follows pertains to plum trees of the newvariety grafted onto Nemaguard rootstock and grown in the vicinity ofFresno, Calif. and is believed to apply to plants of the variety grownin similar conditions of soil and climate elsewhere.

TREE

When grafted on Nemaguard rootstock the tree is of medium size andmedium vigor. It is upright in habit and round in shape. The foliage isof medium density. The trees are hardy, regular bearers and veryproductive.

The trunk is of medium thickness and in surface texture. The branchesare medium in caliper and are of medium surface texture. The brancheshave a dull surface appearance and carry a medium number of medium-sizedlenticels.

LEAVES

In general, leaves are of medium size, having an average length of about9.8 cm. and an average width of about 4.2 cm. Leaves are elliptic inoutline and upfolded in profile. Leaf blade tips curve slightlydownwardly at an acute angle. The crenate leaf margin undulatesslightly. The leaf apex is acuminate; the leaf base is V-shaped. Leavesare of medium thickness. Leaf color on the upper surface is about Green137A. The upper leaf surface is smooth, with no pubescence andsemi-glossy. The lower leaf surface is about Green 137D in color, weakin glossiness and no pubescence is present. The lower leaf surface issmooth in texture and has a dull surface appearance.

The petiole is of medium length and medium thickness. There are usuallythree medium-sized glands oppositely and alternately positioned on boththe leaf base and petiole. Glands are about Green 139D in color.Stipules are persistent.

Wood (leaf) buds are medium in size and conical in shape. The position,relative to the shoot, is slightly held out, their support is of mediumsize and not decurrent. The time of bud burst is medium.

On flowering shoots, anthocyanin is absent. The shoots are of mediumsize and thickness, have a medium internode length with a medium densityof buds on spurs and one year old shoots. The ratio of wood (leaf) budsto flowering buds is about 1/2.

FLOWERS

Flower buds are, in general, hardy, of medium size and length, pointedand freely positioned. There is some pubescence and they are about Brown177A in color.

Flowers first bloom about February 28 and attain full bloom in mediumtime -- on the average, around the first week of March in the vicinityof Fresno, Calif. Blooms have a duration of about 8 days. The fullyopened flower is white in color, of medium size -- about 2.3 cm.,rosaceous in shape and the petals are free.

The peduncle is of medium length, medium thickness and pubescence isabsent.

The receptacle is of medium depth. Pubescence is absent on the innersurface at white bud stage. The outer surface exhibits some pubescence.

Sepals are adpressed to petals, elliptic in shape and with somepubescence on the inner and outer surfaces.

None of the flowers has exhibited double sepals.

Petals are medium in size (about 0.9 cm.); transverse broad elliptic inshape, have medium claw length, weakly wavy margins and a medium baseangle. The division of the upper margins is entire and pubescence isabsent on both inner and outer surfaces and both surfaces. The petalsare white in color.

The stigma is level with the anthers.

The anthers are Yellow 28A (with shadings of Red 45D) just beforedehiscence.

Pollen is Yellow 12D in color.

Stamens are perigynously positioned.

Pistils are few in number, but always at least one.

Pubescence is absent in ovaries and styles.

FRUIT

The fruit, as described, was firm-ripe on June 14th. The fruit at thatstage of its development is uniformly large having an axial diameter ofabout 5.5 cm. and a transverse diameter in the suture plane of about 6.4cm. At right angles to the suture plane, the diameter is about 6.4 cm.,thus indicating a practically uniform, symmetrical and oblate shape, butcompressed transversely. The position of the maximum diameter is towardsthe middle. The fruit is symmetric about the suture line. Fruit ripensearly (averaging mid to late June in Fresno).

The fruit is for market use and has good keeping and shipping qualities.It exhibits average resistance to insects and diseases.

The suture is an inconspicuous line -- discontinuous at the apex. Theventral surface is rounded slightly, with equal lips. The depresion ofthe apex is distinct. The pistil base does not persist. There is nopubescence at the apex.

The stem cavity is rounded, except that it is usually elongated in theplane of the suture, with the suture showing on one side. The depth ofthe cavity is about 1.5 cm., and its width about 2.3 cm. No markings arepresent. The base of the fruit is rounded. The apex is depressed inshape. The pistil point is apical in shape.

The stem is of medium length (about 0.9 cm), glabrous and adheres withmedium strength to the stone.

The skin, which is of medium thickness and of medium texture istenacious to the flesh, displays roughness and reticulation is present.The skin is sour in taste and shows no tendency to crack. Skin color isred-black, Purple 79A to Black 202A (depending on ripeness). Down iswanting and a bloom is present. Skin is not reticulated but possessessome roughness.

The color of the flesh is surrounding the pit cavity and the pit cavityis about Greyed Yellow 160D. The amygdalin is wanting and juice isabundant. The flesh has a medium sugar content. Flesh texture is mediumfirm, fine and meaty. Fibers are few in number and fine and tender.Fruit ripens first at apex and produces fruit of good eating quality.The flavor is acid, mild and delicate. Aroma is wanting. The stone/fleshratio is about 1.5/119 grams.

The stone clings, adhering to flesh over its entire surface. Fibers ofthe stone are short and are retained as short fiber like threads alongthe rides. The stone is of small size, about 2.1 cm. in length and about1.7 cm. in breadth. The width at the stalk end of the stone is about 0.5cm and about 1.1 cm. in thickness. The stalk end is right angled. Theform of the stone in profile is generally globose. The form in ventralview is flattened. The stone's base is straight, its apex pointed andacute. The hilum is oblong. The position of the stone's maximum breadthis toward the middle and the sides and generally equal. The surface ofthe stone is ridged throughout. There is a partly developed outgrowingkeel. The ridges are jagged. The ventral stone edge is thin and wingedthroughout. The dorsal stone edge is narrow with shallow, narrow groovesthroughout and ridges that are continuous on either side. The color ofthe stone is about Greyed Yellow 161C. The stone had a slight tendencyto split during the dry season.

What is claimed is:
 1. A new variety of plum tree cv. Suplumtwenty asillustrated and described.